JP7778422B2 - Insert-molded torsion bar hinge - Google Patents

Description

Torsion hinges are commonly used in many applications and come in many varieties across industry. One example is piano hinges, which feature a coiled torsion spring inserted into the hinge axis. These hinges are typically constructed with a stamped sheet metal bracket, where the coiled spring has a neutral angle tolerance that remains visible in the product, affecting appearance and exposure. Another example, torsion bar hinge designs, typically require the hinge leaves to be stamped separately, a torsion bar formed, and then crimped after assembly, adding play and neutral angle tolerance and potentially further complicating assembly. Other metal torsion spring hinges use a coiled torsion spring inside the hinge barrel, resulting in a larger diameter. Some of these hinges require a stamped sheet metal bracket to be attached to a larger, molded plastic hinge leaf, which requires multiple additional parts and additional assembly steps.

Due to these drawbacks, there is a need for a compact torsion spring hinge design that provides torsion spring torque without the need for additional sleeves or bushings. There is also a need to eliminate riveting and forming operations while still achieving functional and aesthetic benefits. For these and other reasons, there is a need for the present invention.

The accompanying drawings are included to provide a further understanding of the embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the embodiments. Other embodiments and many of the intended advantages of the embodiments will be readily appreciated as they become better understood by reference to the following detailed description. Elements in the drawings are not necessarily to scale relative to one another. Like reference numerals indicate corresponding like parts.

1a-1b illustrate an insert molded torsion bar hinge according to one embodiment. FIG. 1c is an exploded view of an insert molded torsion bar hinge according to one embodiment. FIG. 1d shows a mold cavity for forming the insert molded torsion bar hinge of FIGS. 1a-1c. FIG. 1e is a partially ghosted cross-sectional side view of an insert-molded torsion bar hinge according to one embodiment. FIG. 1f is a partially ghosted detailed view of a portion of an insert molded torsion bar hinge according to one embodiment. FIG. 1g is a detailed view of a portion of an insert molded torsion bar hinge according to one embodiment. FIG. 2a illustrates a molded torsion bar hinge according to one embodiment. FIG. 2b is a detailed view of an insert molded torsion bar hinge according to one embodiment. FIG. 2c is an exploded view of an insert molded torsion bar hinge according to one embodiment. FIG. 3a illustrates an insert molded torsion bar hinge according to one embodiment. FIG. 3b is a cross-sectional view of an insert molded torsion bar hinge according to one embodiment. FIG. 3c is an exploded view of an insert molded torsion bar hinge according to one embodiment. FIG. 4a illustrates an insert molded torsion bar hinge according to one embodiment. FIG. 4b is a cross-sectional view of an insert molded torsion bar hinge according to one embodiment. FIG. 4c is an exploded view of an insert molded torsion bar hinge according to one embodiment. FIG. 5a illustrates an insert molded torsion bar hinge according to one embodiment. FIG. 5b is an exploded view of an insert molded torsion bar hinge according to one embodiment. FIG. 5c is a detailed view of an insert molded torsion bar hinge according to one embodiment. FIG. 5d is a side view of an insert molded torsion bar hinge according to one embodiment. FIG. 5e is a cross-sectional view of an insert molded torsion bar hinge according to one embodiment. FIG. 6a shows a hinged device according to one embodiment. FIG. 6b is an exploded view of a hinged device according to one embodiment. FIG. 6c illustrates an insert molded torsion bar hinge according to one embodiment. FIG. 6d is a cross-sectional view of an insert molded torsion bar hinge according to one embodiment. 7a-7c show a folding system according to one embodiment. 8a-8b show a multi-axis insert molded torsion bar hinge. FIG. 8c is an exploded view of a multi-axis insert molded torsion bar hinge.

DETAILED DESCRIPTION In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the present invention may be practiced. In this regard, directional terms such as "top,""bottom,""front,""back,""leading," and "tail" are used with reference to the orientation of the figures being described. Because components of the embodiments may be positioned in many different orientations, the directional terminology is used for purposes of explanation and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

It should be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless otherwise noted.

Figures 1a-1b show an insert-molded torsion bar hinge 10 according to one embodiment. Figure 1c shows an exploded view of the insert-molded torsion bar hinge 10 according to one embodiment. In one embodiment, the insert-molded torsion bar hinge 10 includes a first hinge element 12, a second hinge element 14, a torsion bar 16, and a knuckle 18. The torsion bar 16 includes a main bar body 16a, a first end 16b, and a second end 16c. In one embodiment, the first hinge element 12 and the second hinge element 14 are rotated relative to one another along the main torsion hinge axis X, and the torsion bar 16 provides a torsion spring torque to the insert-molded torsion bar hinge 10.

In one embodiment, the first end 16b of the torsion bar 16 is fully embedded within the first hinge element 12, and the second end 16c of the torsion bar 16 is fully embedded within the second hinge element 14, while the alternating knuckles 18 from the first hinge element 12 and the second hinge element 14 extend into portions of the main bar body 16a. Thus, when the first hinge element 12 and the second hinge element 14 are rotated relative to one another—for example, when the first hinge element 12 is rotated from the "flat" position of FIG. 1a to the "near-vertical" position of FIG. 1b—the first end 16b of the torsion bar 16 rotates with the first hinge element 12, while the second end 16c is held in place. This rotation of both ends of the torsion bar 16 generates a torsion spring torque in the insert-molded torsion bar hinge 10.

In one embodiment, the position of the first hinge element 12 and the second hinge element 14 in FIG. 1a is a neutral spring position. In that position, the first end 16b and the second end 16c of the torsion bar 16 are unbent and relaxed. When the second hinge element 12, and accordingly the second end 16b, is rotated to the near-vertical position shown in FIG. 1b, the torsion bar 16 moves from its neutral relaxed state to a bent state.

In an embodiment, the first end 16b and the second end 16c are contoured to be secured to the first hinge element 12 and the second hinge element 14, respectively. In one embodiment, the main bar body 16a extends along the primary torsional hinge axis X, while the first end 16b and the second end 16c are contoured to extend in a non-parallel direction from the primary torsional hinge axis X so as to be secured to and rotate with the first hinge element 12 and the second hinge element 14 when embedded within the first hinge element 12 and the second hinge element 14, respectively. Other configurations for contouring the first end 16b and the second end 16c to be secured to the first hinge element 12 and the second hinge element 14 are possible, as will be discussed further below.

In one embodiment, the insert-molded torsion bar hinge 10 is formed using an injection molding process in which molten material is injected into a mold cavity. Injection molding can be done with many materials, including thermoplastic and thermoset polymers. The material for the molded part is fed into a heated barrel, mixed, and injected into the mold cavity, where it cools and hardens to conform to the shape of the cavity.

FIG. 1d shows a mold cavity 20 used to form the insert-molded torsion bar hinge 10. First, the torsion bar 16 is placed into the mold cavity 20. In one embodiment, the mold cavity has a first mold cavity section 22 and a second mold cavity section 24, which are negative images of the first hinge element 12 and the second hinge element 14, respectively, shown in FIG. 1b. The first end 16b of the torsion bar 16 is positioned within the first mold cavity section 22, which forms the first hinge element 12, and the second end 16c is positioned within the second mold cavity section 24, which forms the second hinge element 14. Within the mold cavity 22, the main bar bodies 16a of the torsion bar are alternately positioned between the first mold cavity section 22 and the second mold cavity section 24, and the knuckles 18 are formed on the main bar bodies 16a. In one embodiment, half of the knuckles 18 formed on the torsion bar 16 are part of the first hinge element 12 and are formed in the first mold cavity section 22, and the other half of the knuckles 18 formed on the torsion bar 16 are part of the second hinge element 14 and are formed in the second mold cavity section 24. Other combinations are possible, with one hinge element having more knuckles 18 than the other.

In one embodiment, the first hinge element 12 and the second hinge element 14 can include a wide variety of attachment features simply by including them in the mold cavity, without adding additional cost to the part. These features can include threaded relief holes, snap fits, adhesive pads, studs, and other common methods. Each hinge element can also include cosmetic contours and shapes, along with selected ribs/thicknesses for structural support and various plastic colors and textures, avoiding the additional parts and processing currently required to create torsion spring hinge products.

In one embodiment, the insert-molded torsion bar hinge 10 is formed in a single shot into the first mold cavity portion 22 and the second mold cavity portion 24 of the mold cavity 20. A main runner 21 supplies hot molding material, which is diverted to both the first mold cavity portion 22 and the second mold cavity portion 24 via runners 21a, 21b. Because the insert-molded torsion bar hinge 10 is formed in a single shot into the first mold cavity portion 22 and the second mold cavity portion 24 and over the torsion bar 16, the manufacturing process is significantly simplified, the number of parts is limited, and a torsion hinge device with stable and consistent performance is obtained. As the molding material flows into the first and second mold cavity sections 22, 24, respectively, it completely surrounds and encases the first end 16b of the first hinge element 12 and the second end 16c of the second hinge element 14. The molding material then cools and solidifies in place, isolating the first and second ends 16b, 16c of the torsion bar and eliminating any play between the first and second hinge elements 12, 14 and the second hinge element 14. In one embodiment, the torsion bar 16 is exclusively secured by the molding material forming the first and second hinge elements 12, 14. In this manner, the insert-molded torsion bar hinge 10 is a simpler hinge that does not require the attachment of additional parts or fastening devices.

In conventional torsion hinge designs where the hinge components are press-formed sheet metal brackets, the torsion bar must be bent into position with the hinge components, leaving a gap in the hinge components to allow the bar to be bent and then placed into the hinge components. However, because the first hinge element 12 and second hinge element 14 are molded around the torsion bar 16, no gap or opening is necessary; instead, the molding material completely surrounds and encapsulates the first end 16b and second end 16c of the insert-molded torsion bar hinge 10.

Additionally, by molding directly around the torsion bar 16, the molding position determines the neutral angle of the spring hinge. This eliminates the product variability typical of prior systems, which either bend the torsion bar to the neutral position or use a wound coil spring, introduce a level of product-to-product variability. The mold 22 is configured for the desired neutral angle, with a small tolerance included for ends 16b and 16c. Accordingly, when the molten plastic embraces ends 16b and 16c, any gaps resulting from the torsion bar tolerances are filled, resulting in consistent results from product to product.

FIG. 1e is a partially ghosted cross-sectional side view of an insert-molded torsion bar hinge 10 according to one embodiment. The first hinge element 12 is partially ghosted to reveal the first end 16b extending into the first hinge element 12. The knuckle 18 is also shown in the region between the first hinge element 12 and the second hinge element 14. In one embodiment, the torsion bar 16 has an outer diameter D ₁₆ of 0.080 inches (2.032 mm) and is made of metal. In one embodiment, the knuckle 18 is a molded plastic material and has an outer diameter D ₁₈ of 8 mm. To ensure that the insert-molded torsion bar hinge 10 has stable performance and can withstand strains from use, in one embodiment, the outer diameter D ₁₈ of the knuckle 18 is between 2 and 6 times the outer diameter D ₁₆ of the torsion bar 16. In another embodiment, the outer diameter D ₁₈ of the knuckle 18 is between 1 mm and 8 mm larger than the outer diameter D ₁₆ of the torsion bar 16 .

Additionally, FIG. 1e illustrates how the insert-molded torsion bar hinge 10 accommodates tolerances on the torsion bar 16 during its manufacture. The first end 16b is illustrated with a difference D ₂₀ in its angular position. The torsion bar 16 may not be perfectly straight due to imperfections in its formation. Depending on its formation, the torsion bar may be angled slightly downward, mostly horizontal, or slightly upward when positioned within the mold cavity during formation. However, once the molding material flows and engulfs the first end 16b, its neutral position is set by the relative positions of the first hinge element 12 and the second hinge element 14, so that relative angular position does not affect the performance of the insert-molded torsion bar hinge 10. The same is true for the relative angular position of the second end 16c.

Figure 1f is a partially ghosted detailed view of a portion of an insert-molded torsion bar hinge 10 according to one embodiment. The second end 16c of the torsion bar 16 is fully fixed within the molding material forming the second hinge element 14, and the main bar body 16a extends through the molding material forming the knuckles 18 (of both the first hinge element 12 and the second hinge element 14). The main bar body 16a is formed cylindrically so that it rotates relatively freely within the knuckles 18 as the first hinge element 12 and the second hinge element 14 rotate about the main torsion hinge axis X. However, because the second end 16c extends in a direction non-parallel to the primary torsion hinge axis X and is fully embedded within the molding material of the second hinge element 14, the second end 16c remains fixed within the second hinge element 14 even when the first hinge element 12 and the second hinge element 14 are rotated about the primary torsion hinge axis X. As further illustrated, the torsion bar ends 16b and 16c may be deformed or modified by various methods by which they are fixed to the hinge elements 12 and 14 during the molding process.

As can be seen in Figure 1f, there is also a tolerance in the length of the torsion bar 16. Just as the angular position may not always be exact, as noted above, the length of the torsion bar 16 will also vary slightly along D _20. However, again, the mold cavity 20 will accommodate these slight variations and secure it within the second housing 14 once the mold material flows into and around the second end 16c.

Figure 1g shows a detailed view of a portion of the insert-molded torsion bar hinge 10. In one embodiment, alternating knuckles 18 are formed on each of the first and second hinge elements 12, 14, with the main bar body 16a of the torsion bar 16 secured to the molding material of each knuckle 18. Figure 1g shows the knuckles 18 formed by the molding process of the first and second hinge elements 12, 14. In one embodiment, the number of knuckles 18 provided on the first and second hinge elements 12, 14 to support the torsion bar 16 depends on the torque and movement requirements of the torsion bar 16. In one embodiment, there are at least two knuckles 18 for each torsion bar 16.

In one embodiment, the torsion bar 16 is configured to slide within each knuckle 18 to allow hinging motion and to store torsional spring energy in the torsion bar 16 of the insert-molded torsion bar hinge 10. The knuckles 18 closest to the first end 16b in the hinge element 12 have less relative movement relative to the torsion bar surface than the knuckles 18 located closer to the center of the main bar 16a. The knuckles 18 furthest from the end 16b in the hinge element 12 have more relative movement. The same is true for the second end 16c in the hinge element 14. The plastic of the knuckles 18 in contact with the torsion bar 16 surface is typically configured for a low coefficient of friction, small radius, and low stress due to plastic molding shrinkage. Although there is some friction torque between the knuckle 18 and the torsion bar 16, it is typically configured to be much lower than the spring torque generated in the torsion bar 16 due to the torsional rotation of the torsion bar 16.

In one embodiment, it may be desirable to adjust the friction torque between the knuckle 18 and the torsion bar 16. This can be accomplished in several configurations according to alternative embodiments. In one embodiment, the friction torque between the knuckle 18 and the torsion bar 16 is adjusted by providing a notch 18a in the knuckle 18. In one embodiment, molded plastic material is removed to form the notch 18a in the knuckle 18. In another embodiment, the mold cavity is adjusted to form the notch 18a as part of forming the knuckle 18. In either case, the friction torque between the knuckle 18 with the notch 18a and the torsion bar 16 is reduced compared to a knuckle 18 with a solid 18b. Additionally, the surface finish of the torsion bar 16 can be adjusted to increase or decrease friction. The choice of plastic material, the use of plastic additives, and the use of torsion bar coatings may also be used to adjust the friction torque.

Figures 2a-2b illustrate an insert-molded torsion bar hinge 40 according to one embodiment. Figure 2c illustrates an exploded view of the insert-molded torsion bar hinge 40 according to one embodiment. In one embodiment, the insert-molded torsion bar hinge 40 includes a first hinge element 42, a second hinge element 44, a first torsion bar 46, and a knuckle 48 (only a few of which are labeled for clarity). In one embodiment, the insert-molded torsion bar hinge 40 further includes a second torsion bar 56, a third torsion bar 66, and a fourth torsion bar 76. In one embodiment, the additional torsion bars 56, 66, and 76 are axially spaced apart on the same primary torsion hinge axis X. In one embodiment, the additional torsion bars are configured to accommodate longer hinge lengths and/or higher torque requirements in some applications. Furthermore, the additional torsion bars improve the torque consistency of the insert-molded torsion bar hinge 40.

Similar to hinge 10 described above, the first end 46c of the torsion bar 46 is fully embedded within the first hinge element 42, and the second end 46b of the torsion bar 46 is fully embedded within the second hinge element 44, while alternating knuckles 48 from the first hinge element 42 and the second hinge element 44 extend into portions of the main bar body 46a of the torsion bar 46. The second torsion bar 56, the third torsion bar 66, and the fourth torsion bar 76 are similarly embedded. Thus, when the first hinge element 42 and the second hinge element 44 are rotated relative to one another, the first ends of the torsion bars 46-76 rotate with the first hinge element 42, while the second ends of the torsion bars 46-76 are held in place. This rotation of the ends of the torsion bars 46-76 creates a torsion spring torque in the insert-molded torsion bar hinge 40.

Although four torsion bars are shown in Figures 2a-2c, more or fewer may be used. Furthermore, the length of each torsion bar, and the number of torsion bars in each, can be selected to control the spring constant of the hinge 10. However, because all of the torsion bars are molded together at once, this embodiment eliminates the play and tolerance buildup that occurs with known hinges due to bending and assembly.

In one embodiment, the first through fourth torsion bars 46, 56, 66, and 76 can be translated or mirrored to additional positions as needed to provide leg forces at desired locations to the first hinge element 42 and second hinge element 44, which move relative to one another. In one embodiment, the insert-molded torsion bar hinge 40 is formed by injection molding in a mold cavity similar to that described above with reference to FIG. 1d. The torsion bars 46-76 are placed in the mold prior to injecting material into the cavity, so that the mold material of the first hinge element 42 and second hinge element 44 directly contacts and completely surrounds the ends of the torsion bars 46-76.

Figures 3a-3b illustrate an insert-molded torsion bar hinge 80 according to one embodiment. Figure 3c illustrates an exploded view of the insert-molded torsion bar hinge 80 according to one embodiment. In one embodiment, the insert-molded torsion bar hinge 80 includes a first hinge element 82, a second hinge element 84, a first torsion bar 86, and a knuckle 88 (only some of which are labeled for clarity).

In one embodiment, the insert-molded torsion bar hinge 80 further includes a first toe support and impact bar 90 and a second toe support and impact bar 92. In one embodiment, the first toe support and impact bar 90 and the second toe support and impact bar 92 further distribute forces from the ends of the torsion bar 86 along the first hinge element 82 and the second hinge element 84 and also provide some resistance to impacts under misuse conditions that could damage the knuckle 88 or the hinge elements 82 and 84. In one embodiment, the first toe support and impact bar 90 and the second toe support and impact bar 92 also include notches 90a and 92a configured to extend partially around the torsion bar 86 to add more support.

As seen in FIG. 3b, the first toe support and impact bar 90 and the second toe support and impact bar 92 are spaced apart from the torsion bar 86 so that the molding material of the first hinge element 82 and the second hinge element 84 completely surrounds the torsion bar 86. In one embodiment, the insert-molded torsion bar hinge 80 is formed by injection molding in a mold cavity similar to that described above with respect to FIG. 1d. The torsion bar 86, the first toe support and impact bar 90, and the second toe support and impact bar 92 are positioned within the mold prior to injecting material into the cavity. Within the cavity, the first toe support and impact bar 90 and the second toe support and impact bar 92 are positioned away from the torsion bar 86 so that the molding material completely surrounds the end of the torsion bar 86 and forms directly around the torsion bar 86, with no impact bars 90 and 92 or anything else intervening between the mold material of the first hinge element 82 and the second hinge element 84 and the torsion bar 86.

Figures 4a-4b show an insert-molded torsion bar hinge 110 according to one embodiment. Figure 4c is an exploded view of the insert-molded torsion bar hinge 110 according to one embodiment. In one embodiment, the insert-molded torsion bar hinge 110 includes a first hinge element 112, a second hinge element 114, a first torsion bar 115, a second torsion bar 116, and a knuckle 118. The first torsion bar 115 includes a main bar body 115a, a first end 115b, and a second end 115c. The second torsion bar 116 includes a main bar body 116a, a first end 116b, and a second end 116c. In one embodiment, the first hinge element 112 and the second hinge element 114 are rotated relative to one another along the primary torsion hinge axis X, and the first torsion bar 115 and the second torsion bar 116 provide a torsion spring torque to the insert-molded torsion bar hinge 110. In one embodiment, as shown, the provision of two parallel torsion bars 115, 116 within a single insert-molded torsion bar hinge 110 can produce twice the spring force achievable with known designs of similar size and configuration.

In one embodiment, the first end 115b of the first torsion bar 115 is fully embedded within the first hinge element 112 and the second end 115c of the first torsion bar 115 is fully embedded within the second hinge element 114, while the alternating knuckles 118 from the first hinge element 112 and the second hinge element 114 extend into a portion of the main bar body 115a of the first torsion bar 115. Similarly, the first end 116b of the second torsion bar 116 is fully embedded within the first hinge element 112, and the second end 116c of the second torsion bar 116 is fully embedded within the second hinge element 114, while alternating knuckles 118 from the first hinge element 112 and the second hinge element 114 extend into portions of the main bar body 116a of the second torsion bar 116. In this manner, when the first hinge element 112 and the second hinge element 114 rotate relative to one another, the first ends 115b and 116b of the torsion bars 115 and 116 rotate with the first hinge element 112, and the second ends 115c and 116c rotate with the second hinge element 114. This relative rotation of the ends of torsion bars 115 and 116 generates a torsion spring torque in the insert-molded torsion bar hinge 110.

In one embodiment, the first torsion bar 115 and the second torsion bar 116 are molded into the insert-molded torsion bar hinge 110 using injection-molded plastic similar to that described above with respect to FIG. 1d. In one embodiment, the insert-molded torsion bar hinge 110 is molded in a single shot over the first torsion bar 115 and the second torsion bar 116. Each of the first torsion bar 115 and the second torsion bar 116 is aligned with the primary torsion hinge axis X at one end (115c, 116b) and connected off-axis at the other end (115b and 116c). This configuration provides twice the torque for a given length as the single bar design described previously.

In one embodiment, more complex hinge shapes and features may be desired. In such cases, it may be preferable to form the first hinge element 112 and the second hinge element 114 in multiple steps or shots.

In one embodiment, the first ends 115b, 116b and second ends 115c, 116c of the torsion bars 115 and 116 are contoured to be fixed to the first hinge element 112 and the second hinge element 114, respectively. Similar to the above embodiment, the main bar body 115a of the first torsion bar 115 is cylindrical, and a portion of the main bar body 115a extends along the primary torsion hinge axis X, while the first end 115b and the second end 115c of the first torsion bar 115 are contoured to extend in a non-parallel direction from the primary torsion hinge axis X. In this manner, when embedded within the first hinge element 112 and the second hinge element 114, respectively, the first torsion bar 115 is fixed to and rotates with the first hinge element 112 and the second hinge element 114.

While the main bar body 116a of the second torsion bar 116 is also cylindrical, the first and second ends 116b, 116c of the second torsion bar 116 are non-cylindrical and have contours that are at least partially flat. Thus, when embedded within the first and second hinge elements 112, 114, respectively, the first end 116b is fixed to the first hinge element 112 and cannot move relative to it, and the second end 116c is fixed to the second hinge element 114 and cannot move relative to it. Other contours can also ensure that the respective torsion bar ends are secured within the first and second hinge elements 112, 114. For example, headed shapes such as square, hexagonal, or splined ends can be used. When the first hinge element 112 and the second hinge element 114 are molded directly onto these shapes, the shapes are fixed to the hinge elements.

The insert-molded torsion bar hinges 10, 40, 80, and 110 have a variety of useful applications where it is desirable to have torsion spring torque between two or more hinge elements. FIG. 5A illustrates one such exemplary application in a hinged device 200 according to one embodiment. In one embodiment, the hinged device 200 includes a hinge cover 202, a container housing 204, and an insert-molded torsion bar hinge 240. In one embodiment, the hinged device 200 is an automobile center console. In one embodiment, the insert-molded torsion bar hinge 240 provides consistent and predictable torsion spring torque for opening and closing the hinge cover 202 on the container housing 204. In one embodiment, the insert-molded torsion bar hinge 240 allows the console hinge cover 202 to pop up upon release of a latch or other control (not shown).

FIG. 5b shows an exploded perspective view of the hinged device 200, and FIGS. 5c-5e show detailed side and cross-sectional views of the insert-molded torsion bar hinge 240. In one embodiment, the hinge cover 202 includes first and second slots 206 (only one of which is visible in FIG. 5b; the other is identical on the opposite side), and the container housing 204 similarly includes first and second slots 208 on either side of the container housing 204. The slots 206 and 208 are positioned to align the insert-molded torsion bar hinge 240 at a desired neutral angle and, together with the spring constant, provide a hinge preload when fully closed. The insert-molded torsion bar hinge 240 includes a first hinge element 242, a second hinge element 244, a third hinge element 246, and a fourth hinge element 248, and further includes a first torsion bar 250 and a second torsion bar 252.

In one embodiment, a first end of the first torsion bar 250 is embedded within the first hinge element 242, and a second end of the first torsion bar 250 is embedded within the third hinge element 246. A first end of the second torsion bar 252 is embedded within the second hinge element 244, and a second end of the second torsion bar 252 is embedded within the fourth hinge element 248. The insert-molded torsion bar hinge 240 can be manufactured in a single-shot molding process, as described above for the other embodiments. As with the previous embodiment, the molding compound of the hinge elements completely surrounds and directly encapsulates the ends of the torsion bars, each of which includes contoured features, such that there is no relative movement between the ends of the torsion bars and the hinge elements.

In operation, the insert-molded torsion bar hinge 240 is coupled to the hinged device 200 such that the first hinge element 242 is disposed within the first slot 206 of the hinge cover 202, the fourth hinge element 248 is disposed within the second slot 206 of the hinge cover 202, the second hinge element 244 is disposed within the first slot 208 of the container housing 204, and the third hinge element 246 is disposed within the second slot 208 of the container housing 204. The first torsion bar 250 and the second torsion bar 252 provide torsion spring torque for opening and closing the hinge cover 202 on the container housing 204.

Figures 6a-6b illustrate another exemplary application of the hinged device 200 according to one embodiment. In one embodiment, the hinged device 200 includes a hinge cover 202, a container housing 204, and an insert-molded torsion bar hinge 280. In one embodiment, the hinged device 200 is a center console for an automobile. In one embodiment, the insert-molded torsion bar hinge 280 provides a consistent and predictable torsion spring torque for opening and closing the hinge cover 202 on the container housing 204.

6c-6d illustrate an insert-molded torsion bar hinge 280 according to one embodiment. In one embodiment, the insert-molded torsion bar hinge 280 provides an alternative means for hingedly connecting the hinge cover 202 and the container housing 204. In one embodiment, the insert-molded torsion bar hinge 280 includes a first hinge element and a second hinge element 284, and further includes a torsion bar 290. For example, in one embodiment, the first hinge element 282 is disposed within the first slot 206 of the hinge cover 202, and the second hinge element 284 is disposed within the first slot 208 of the container housing 204. The insert-molded torsion bar hinge 280 provides torsion spring torque for opening and closing the hinge cover 202 on the container housing 204. In one embodiment, the insert-molded torsion bar hinge 280 can be disposed on both sides of the hinged device 200. In another embodiment, an insert molded torsion bar hinge 280 can be placed on one side of the hinged device 200, with a plain pivot or friction hinge 295 placed on the other side, as desired.

In one embodiment, a first end of the first torsion bar 290 is embedded within the first hinge element 282, and a second end of the torsion bar 290 is embedded within the second hinge element 284. The insert-molded torsion bar hinge 280 can be manufactured in a single-shot molding process, as described above for the other embodiments. As with the previous embodiment, the molding material of the hinge element completely surrounds and directly encapsulates each of the torsion bar ends, each of which includes contoured features, so that there is no relative movement between the torsion bar ends and the hinge element. Also, as with the previous embodiment, a circular cross-section torsion bar is used as the pivot axis. When the first hinge element 282 and the second hinge element 284 are rotated relative to one another, the torsion bar 290 pivots along the primary torsion hinge axis, providing a torsion spring torque.

Figures 7A-7C illustrate a folding system 300 according to one embodiment. In one embodiment, the folding system 300 includes a base 310, a folding member 312, and an insert-molded torsion bar hinge 340. In one embodiment, the insert-molded torsion bar hinge 340 includes a fixed hinge side 344 and a spring-loaded side 342. In operation, the folding member 312 has an open position (shown in Figures 7a and 7c) and a folded position (shown in Figure 7b). When the folding member 312 is folded against the base 310, a gap 315 remains. In one embodiment, the insert-molded torsion bar hinge 340 is positioned such that its torsion spring torque automatically covers the gap 315 when the folding member 312 is folded against the base 310, allowing the folding member 312 to present a smooth, flat surface when folded.

Such gap concealers are useful in a variety of applications, such as pickup trucks, where the folding member 312 can be a truck tailgate, a truck midgate with the option to extend the cargo bed into the cab, a typical folding rear seat, or any of a variety of other divider panels.

In one embodiment, the insert-molded torsion bar hinge 340 is injection molded in a single shot over one or more torsion bars, as described above with respect to the insert-molded torsion bar hinges 10, 40, and 80. The insert-molded torsion bar hinge 340 may have one or more torsion bars that include a contoured recessed end, with a fixed hinge side 344 on one end and a spring-loaded side 342 on the other end. By attaching the fixed hinge side 344 to the base 310 and loading the recessed torsion bar to press the spring-loaded side 342 against the folding member 312, the torsion bar hinge 340 folds over the gap 315 when the folding member 312 is folded relative to the base 310.

The fixed hinge side 344 can have any number of mounting options, such as screw clearance holes, adhesive fastening, snap fits, studs, etc., for securing to the base 310. The spring-loaded side 342 can include various cosmetic contours and shapes, along with rib thicknesses for structural support.

The insert-molded torsion bar hinge 340 has a smaller barrel size than conventional hinges and eliminates the separate coil springs commonly used in conventional hinges, resulting in a cleaner appearance and eliminating the potential for tangling associated with coil springs. The insert-molded torsion bar hinge 340, as described above, is made in a single injection molding process, can easily incorporate a variety of plastic colors and textures, and avoids the additional parts and processing currently required to create a finished product known in the art.

8a-8b show diagrams illustrating a multi-axis insert-molded torsion bar hinge 380 according to one embodiment. FIG. 8c shows an exploded view of the multi-axis insert-molded torsion bar hinge 380 according to one embodiment. In one embodiment, the multi-axis insert-molded torsion bar hinge 380 includes a first hinge element 382, a second hinge element 384, and a third hinge element 386, as well as a first torsion bar 390 and a second torsion bar 392. The multi-axis insert-molded torsion bar hinge 380 is similar to the torsion hinges described above, but has two axes of rotation ( _X1 and _X2 ) instead of one.

In one embodiment, each of the first torsion bar 390 and the second torsion bar 392 includes a main bar body 390a, 392a, a first end 390b, 392b, and a second end 390c, 392c. The main bar body 390a of the first torsion bar 390 lies on a first axis _X1 , and the main bar body 392a of the second torsion bar 392 lies on a second axis _X2 . In one embodiment, the first ends 390b, 392b and second ends 390c, 392c are contoured to extend in a direction non-parallel to the axes _X1 and _X2 . In other embodiments, other contours, such as flattened portions, may be used.

In one embodiment, a first end of the first torsion bar 390b is embedded within the second hinge element 384, a second end of the first torsion bar 390c is embedded within the first hinge element 382, a first end of the second torsion bar 392b is embedded within the third hinge element 386, and a second end of the second torsion bar 392c is embedded within the second hinge element 384. The insert-molded torsion bar hinge 380 can be manufactured in a single-shot molding process, as described above for the other embodiments. As with the previous embodiment, the molding compound of the hinge element completely surrounds and directly encapsulates each of the torsion bar ends, each of which includes contoured features, such that there is no relative movement between the torsion bar ends and the hinge element.

Additionally, knuckles 388 (only a few are labeled for simplicity) are formed on each of the first hinge element 382, second hinge element 384, and third hinge element 386 such that the knuckles 388 from the first hinge element 382 and second hinge element 384 are formed directly over the main bar body 390a of the first torsion bar 390, and the knuckles 388 from the second hinge element 384 and third hinge element 386 are formed directly over the main bar body 392a of the second torsion bar 392. Because the main bar bodies 390a, 392a of the torsion bars 390, 392 are cylindrical, the torsion bar 390 rotates within the knuckle 388 as the first hinge element 382 and the second hinge element 384 rotate relative to one another along the first axis _X1 , and the torsion bar 392 rotates within the knuckle 388 as the second hinge element 384 and the third hinge element 386 rotate relative to one another along the second axis _X2 . Additional hinge elements and torsion bars may be added to provide additional hinge sections as needed.

While specific embodiments have been illustrated and described herein, those skilled in the art will recognize that various alternative and/or equivalent implementations may be substituted for the specific embodiments illustrated and described without departing from the scope of the invention. This application is intended to cover any adaptations or variations of the specific embodiments described herein. Accordingly, it is intended that the invention be limited only by the claims and equivalents thereof.
[Aspect 1]
An insert molded torsion bar hinge,
a cylindrical metal torsion bar having a main bar body extending partially along a torsion bar axis, and first and second profiled bar ends at opposite ends of the main bar body;
a molded plastic first hinge element including a first knuckle, the first hinge element molded to directly cover and encompass the first profiled bar end such that the first profiled bar end is fixed within the first hinge element and cannot rotate relative to the first hinge element, and the first knuckle molded to directly cover and encompass a portion of the main bar body;
a molded plastic second hinge element including a second knuckle molded to directly cover and encompass the second profiled bar end such that the second profiled bar end is fixed within the second hinge element and cannot rotate relative to the second hinge element, and the second knuckle molded to directly cover and encompass a portion of the main bar body;
the first hinge element and the second hinge element are configured for relative rotation to one another along the torsion bar axis, and the torsion bar generates a torsion spring torque due to the relative rotation of the first hinge element and the second hinge element.
[Aspect 2]
2. The insert-molded torsion bar hinge of claim 1, wherein there is no coil between the molded plastic of the first hinge element and the first bar end, and there is no coil between the molded plastic of the second hinge element and the second bar end.
[Aspect 3]
3. The insert-molded torsion bar hinge of claim 1 or 2, configured as a piano hinge, wherein the first hinge element further comprises a third knuckle configured on the main bar body and the second hinge element further comprises a fourth knuckle configured on the main bar body.
[Aspect 4]
Aspects 4. The insert-molded torsion bar hinge of any one of aspects 1 to 3, wherein the first knuckle and the third knuckle of the first hinge element are alternately arranged with the second knuckle and the fourth knuckle of the second hinge element along the main bar body.
[Aspect 5]
Aspect 5. The insert-molded torsion bar hinge of any one of aspects 1-4, wherein the cylindrical metal torsion bar is in exclusive contact with the first hinge element and the second hinge element.
[Aspect 6]
Aspects 6. The insert-molded torsion bar hinge of any one of aspects 1-5, wherein the first bar end and the second bar end are contoured to extend in a direction non-parallel to the torsion bar axis or to have a non-cylindrical shape such that when contained within the first hinge element and the second hinge element, the contoured ends are fixed within the hinge elements and cannot rotate relative to the hinge elements.
[Aspect 7]
Aspects 7. The insert-molded torsion bar hinge of any one of aspects 1 to 6, wherein a friction torque between the knuckle and the torsion bar is reduced by providing a notch in the knuckle.
[Aspect 8]
Aspect 8. The insert molded torsion bar hinge of any one of aspects 1-7, further comprising an impact bar embedded within at least the first hinge element or the second hinge element.
[Aspect 9]
further comprising an additional cylindrical metal torsion bar having a main bar body extending in part along the torsion bar axis, and first and second profiled bar ends at opposite ends of the main bar body;
the first hinge element of molded plastic is molded to directly cover and encompass the first profiled bar end of the additional torsion bar such that the first profiled bar end is fixed within the first hinge element and cannot rotate relative to the first hinge element;
Aspects 9. The insert-molded torsion bar hinge of any one of aspects 1-8, wherein the molded plastic second hinge element is molded to directly cover and encompass the second profiled bar end of the additional torsion bar such that the second profiled bar end is fixed within the second hinge element and cannot rotate relative to the second hinge element.
[Aspect 10]
at least three cylindrical metal torsion bars each including a main bar body extending in part along a torsion bar axis and a first profiled bar end and a second profiled bar end at opposite ends of the main bar body;
the first hinge element of molded plastic is molded to directly cover and encompass the first profiled bar ends of the at least three cylindrical torsion bars such that the first profiled bar ends are fixed within the first hinge element and cannot rotate relative to the first hinge element;
10. The insert-molded torsion bar hinge of claim 9, wherein the molded plastic second hinge element is molded to directly cover and encompass the second profiled bar ends of the at least three cylindrical torsion bars such that the second profiled bar ends are fixed within the second hinge element and cannot rotate relative to the second hinge element.
[Aspect 11]
10. The insert-molded torsion bar hinge of claim 9, further comprising: a molded plastic third hinge element comprising a first knuckle molded to directly overlay and encompass the first profiled bar end of the additional cylindrical metal torsion bar such that the first profiled bar end is fixed within the first hinge element and cannot rotate relative to the first hinge element, and the first knuckle molded to directly overlay and encompass a portion of the main bar body of the additional cylindrical metal torsion bar.
[Aspect 12]
A method for forming an insert molding torsion bar hinge, comprising:
placing a cylindrical metal torsion bar into a mold cavity, the torsion bar comprising a main bar body extending in part along a torsion bar axis, a first profiled bar end and a second profiled bar end at opposite ends of the main bar body, the mold cavity comprising a first mold cavity portion and a second mold cavity portion;
placing a cylindrical metal torsion bar into the mold cavity, the first profiled bar end being contained exclusively within the first mold cavity section, the second profiled bar end being contained exclusively within the second mold cavity section, and a portion of the main bar body being contained within both the first mold cavity section and the second mold cavity section;
injection molding a fluid plastic into the first mold cavity section so as to directly overlay and completely encompass the first contoured bar end and directly overlay and completely encompass at least a portion of the main bar body;
solidifying the fluid plastic in the first mold cavity portion, thereby forming a molded plastic first hinge element including the first contoured bar end and with a first knuckle including at least a portion of the main bar body;
injection molding a fluid plastic into the second mold cavity section so as to directly overlay and completely enclose the second profiled bar end and directly overlay and completely enclose at least a portion of the main bar body;
solidifying the fluid plastic in the second mold cavity portion, thereby forming a molded plastic second hinge element including the second contoured bar end and with a second knuckle including at least a portion of the main bar body, the first hinge element and the second hinge element being configured for relative rotation with respect to one another along the torsion bar axis;
A method for forming an insert molded torsion bar hinge, comprising:
[Aspect 13]
Aspect 13. The method of forming an insert-molded torsion bar hinge of aspect 12, comprising injecting the fluid plastic into the first mold cavity portion and the second mold cavity portion in a single shot.
[Aspect 14]
Aspect 14. The method of forming an insert-molded torsion bar hinge of aspect 12 or 13, further comprising injecting the fluid plastic into the first mold cavity portion and the second mold cavity portion in separate shots.
[Aspect 15]
Aspect 15. The method of forming an insert-molded torsion bar hinge of any one of aspects 12-14, further comprising forming a plurality of knuckles on both the first hinge element and the second hinge element that are alternately positioned along the main bar body.
[Aspect 16]
Aspects 16. The method of forming an insert-molded torsion bar hinge of any one of aspects 12-15, wherein the torsion bar generates a torsion spring torque due to the relative rotation of the first hinge element and the second hinge element.
[Aspect 17]
1. A folding system comprising:
With base;
a folding member hingedly connected to the base so as to be foldable relative to the base;
an insert-molded torsion bar hinge having a fixed hinge side and a spring-loaded side, the fixed hinge side being fixed to the base and the spring-loaded side being rotatable with the folding member;
The insert-molded torsion bar hinge is
a cylindrical metal torsion bar having a main bar body extending in part along a torsion bar axis, and first and second profiled bar ends on opposite sides of the main bar body;
the fixed hinge side is constructed from molded plastic and includes a first knuckle molded to directly cover and encompass the first profiled bar end such that the first profiled bar end is fixed within the fixed hinge side and is non-rotatable relative to the fixed hinge side, the first knuckle being molded to directly cover and encompass a portion of the main bar body;
the spring-loaded side is constructed from molded plastic and includes a second knuckle molded to directly cover and encompass the second profiled bar end such that the second profiled bar end is fixed within the spring-loaded side and cannot rotate relative to the spring-loaded side, the second knuckle being molded to directly cover and encompass a portion of the main bar body;
the fixed hinge side and the spring-loaded side are configured to rotate relative to each other along the torsion bar axis, and the torsion bar generates a torsion spring torque due to the relative rotation between the fixed hinge side and the spring-loaded side.
Folding system.
[Aspect 18]
An insert molded torsion bar hinge,
a first hinge element;
a second hinge element;
a cylindrical metal torsion bar having a main bar body extending in part along a torsion bar axis, and first and second profiled bar ends at opposite ends of the main bar body;
the first hinge element comprises molded plastic molded to directly cover and encompass the first profiled bar end such that the first profiled bar end is fixed within the first hinge element and cannot rotate relative to the first hinge element;
the second hinge element comprises a molded plastic molded to directly cover and encompass the second profiled bar end such that the second profiled bar end is fixed within the second hinge element and is non-rotatable relative to the second hinge element;
the first hinge element and the second hinge element are coaxially aligned on the torsion bar axis and configured for relative rotation with respect to one another along the torsion bar axis, and the torsion bar generates a torsion spring torque due to the relative rotation.
Insert-molded torsion bar hinges.
[Aspect 19]
19. The insert-molded torsion bar hinge of claim 18, wherein the first hinge element and the second hinge element are adjacent to one another, and the torsion bar is curved so that it extends from the first hinge element through the second hinge element and bends back into the second hinge element.
[Aspect 20]
20. The insert-molded torsion bar hinge of claim 18 or 19, further comprising: the first hinge element and the second hinge element are adjacent to one another; and the torsion bar is curved so that it extends from the first hinge element through the second hinge element and bends back into the second hinge element.

Claims (19)

An insert molded torsion bar hinge,
a cylindrical metal torsion bar having a main bar body extending partially along a torsion bar axis, and first and second profiled bar ends at opposite ends of the main bar body;
a molded plastic first hinge element including a first knuckle that surrounds the first profiled bar end such that the first profiled bar end is fixed within the first hinge element and cannot rotate relative to the first hinge element, the first knuckle surrounding a portion of the main bar body ;
a molded plastic second hinge element including a second knuckle that surrounds the second profiled bar end such that the second profiled bar end is fixed within the second hinge element and cannot rotate relative to the second hinge element, the second knuckle surrounding a portion of the main bar body ;
The insert-molded torsion bar hinge, wherein the first hinge element and the second hinge element are configured to rotate relative to one another along the torsion bar axis, and the cylindrical metal torsion bar generates a torsion spring torque due to the relative rotation of the first hinge element and the second hinge element. The insert-molded torsion bar hinge of claim 1, characterized in that there is no coil between the molded plastic of the first hinge element and the first contoured bar end, and there is no coil between the molded plastic of the second hinge element and the second contoured bar end. 2. The insert-molded torsion bar hinge of claim 1, configured as a piano hinge, wherein the first hinge element further comprises a third knuckle surrounding the main bar body and the second hinge element further comprises a fourth knuckle surrounding the main bar body. The insert-molded torsion bar hinge of claim 3, wherein the first knuckle and the third knuckle of the first hinge element are alternately arranged with the second knuckle and the fourth knuckle of the second hinge element along the main bar body. The insert-molded torsion bar hinge of claim 1, wherein the cylindrical metal torsion bar is in exclusive contact with the first hinge element and the second hinge element. The insert-molded torsion bar hinge of claim 1, wherein the first profiled bar end and the second profiled bar end are profiled to extend in a direction non-parallel to the torsion bar axis or to have a non-cylindrical shape, such that when contained within the first hinge element and the second hinge element, the first profiled bar end and the second profiled bar end are fixed within the first hinge element and the second hinge element, respectively, and are unable to rotate relative to the first hinge element and the second hinge element, respectively. The insert-molded torsion bar hinge of claim 1, wherein the friction torque between the knuckle and the cylindrical metal torsion bar is reduced by providing a notch in the knuckle. The insert-molded torsion bar hinge of claim 1, further comprising an impact bar embedded within at least the first hinge element or the second hinge element. further comprising an additional cylindrical metal torsion bar having a main bar body extending in part along the torsion bar axis, and first and second profiled bar ends at opposite ends of the main bar body;
the first hinge element of molded plastic surrounds the first profiled bar end of the additional cylindrical metal torsion bar such that the first profiled bar end is fixed within the first hinge element and cannot rotate relative to the first hinge element;
9. The insert-molded torsion bar hinge of any one of claims 1 to 8, wherein the second hinge element of molded plastic surrounds the second profiled bar end of the additional cylindrical metal torsion bar such that the second profiled bar end is fixed within the second hinge element and cannot rotate relative to the second hinge element. at least three cylindrical metal torsion bars each including a main bar body extending in part along a torsion bar axis and a first profiled bar end and a second profiled bar end at opposite ends of the main bar body;
the first hinge element of molded plastic surrounds the first profiled bar ends of the at least three cylindrical metal torsion bars such that the first profiled bar ends are fixed within the first hinge element and cannot rotate relative to the first hinge element;
10. The insert-molded torsion bar hinge of claim 9, wherein the second hinge element of molded plastic surrounds the second profiled bar ends of the at least three cylindrical metal torsion bars such that the second profiled bar ends are fixed within the second hinge element and cannot rotate relative to the second hinge element. 10. The insert-molded torsion bar hinge of claim 9, further comprising: a molded plastic third hinge element comprising a first knuckle that surrounds the first profiled bar end of the additional cylindrical metal torsion bar such that the first profiled bar end is fixed within the third hinge element and cannot rotate relative to the third hinge element, and the first knuckle surrounds a portion of the main bar body of the additional cylindrical metal torsion bar. A method for forming an insert molding torsion bar hinge, comprising:
placing a cylindrical metal torsion bar into a mold cavity, the cylindrical metal torsion bar comprising a main bar body extending in part along a torsion bar axis, first and second profiled bar ends at opposite ends of the main bar body, the mold cavity comprising a first mold cavity portion and a second mold cavity portion;
placing a cylindrical metal torsion bar into the mold cavity, the first profiled bar end being contained exclusively within the first mold cavity section, the second profiled bar end being contained exclusively within the second mold cavity section, and a portion of the main bar body being contained within both the first mold cavity section and the second mold cavity section;
injection molding a fluid plastic into the first mold cavity section so as to directly overlay and completely encompass the first contoured bar end and directly overlay and completely encompass at least a portion of the main bar body;
solidifying the fluid plastic in the first mold cavity portion, thereby forming a molded plastic first hinge element including the first contoured bar end and with a first knuckle including at least a portion of the main bar body;
injection molding a fluid plastic into the second mold cavity section so as to directly overlay and completely enclose the second profiled bar end and directly overlay and completely enclose at least a portion of the main bar body;
solidifying the fluid plastic in the second mold cavity portion, thereby forming a molded plastic second hinge element including the second contoured bar end and with a second knuckle including at least a portion of the main bar body, the first hinge element and the second hinge element being configured for relative rotation with respect to one another along the torsion bar axis;
A method for forming an insert molded torsion bar hinge, comprising: The method for forming an insert-molded torsion bar hinge according to claim 12, further comprising: injecting the fluid plastic into the first mold cavity portion and the second mold cavity portion in a single shot. The method for forming an insert-molded torsion bar hinge according to claim 12, further comprising injecting the fluid plastic into the first mold cavity portion and the second mold cavity portion in separate shots. The method for forming an insert-molded torsion bar hinge according to claim 12, further comprising forming a plurality of knuckles on both the first hinge element and the second hinge element, the knuckles being arranged alternately along the main bar body. The insert-molding torsion bar hinge forming method described in any one of claims 12 to 15, wherein the cylindrical metal torsion bar generates a torsion spring torque due to the relative rotation of the first hinge element and the second hinge element. 1. A folding system comprising:
With base;
a folding member hingedly connected to the base so as to be foldable relative to the base;
an insert-molded torsion bar hinge having a fixed hinge side and a spring-loaded side, the fixed hinge side being fixed to the base and the spring-loaded side being rotatable with the folding member;
The insert-molded torsion bar hinge is
a cylindrical metal torsion bar having a main bar body extending in part along a torsion bar axis, and first and second profiled bar ends on opposite sides of the main bar body;
the fixed hinge side is constructed from molded plastic and includes a first knuckle surrounding the first profiled bar end such that the first profiled bar end is fixed within the fixed hinge side and is non-rotatable relative to the fixed hinge side, the first knuckle surrounding a portion of the main bar body;
the spring-loaded side is constructed from molded plastic and includes a second knuckle surrounding the second profiled bar end such that the second profiled bar end is fixed within the spring-loaded side and cannot rotate relative to the spring-loaded side, the second knuckle surrounding a portion of the main bar body ;
The fixed hinge side and the spring-loaded side are configured to rotate relative to each other along the torsion bar axis, and the cylindrical metal torsion bar generates a torsion spring torque by the relative rotation between the fixed hinge side and the spring-loaded side.
Folding system. An insert molded torsion bar hinge,
a first hinge element;
a second hinge element;
a cylindrical metal torsion bar having a main bar body extending in part along a torsion bar axis, and first and second profiled bar ends at opposite ends of the main bar body;
the first hinge element comprises molded plastic surrounding the first profiled bar end such that the first profiled bar end is fixed within the first hinge element and cannot rotate relative to the first hinge element;
the second hinge element comprises molded plastic surrounding the second profiled bar end such that the second profiled bar end is fixed within the second hinge element and cannot rotate relative to the second hinge element;
the first hinge element and the second hinge element are coaxially aligned on the torsion bar axis and configured for relative rotation with respect to one another along the torsion bar axis, and the cylindrical metal torsion bar generates a torsion spring torque due to the relative rotation.
Insert-molded torsion bar hinges. The insert-molded torsion bar hinge of claim 18, wherein the first hinge element and the second hinge element are adjacent to one another, and the cylindrical metal torsion bar is curved so that it extends from the first hinge element through the second hinge element and bends back into the second hinge element.